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The Single UNIX &reg; Specification, Version 2<br>
Copyright &copy; 1997 The Open Group

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<h4><a name = "tag_000_008_645">&nbsp;</a>NAME</h4><blockquote>
sigismember - test for a signal in a signal set
</blockquote><h4><a name = "tag_000_008_646">&nbsp;</a>SYNOPSIS</h4><blockquote>
<pre><code>

#include &lt;<a href="signal.h.html">signal.h</a>&gt;

int sigismember(const sigset_t *<i>set</i>, int <i>signo</i>);
</code>
</pre>
</blockquote><h4><a name = "tag_000_008_647">&nbsp;</a>DESCRIPTION</h4><blockquote>
The
<i>sigismember()</i>
function tests whether the signal specified by <i>signo</i> is a
member of the
set pointed to by <i>set</i>.
<p>
Applications should call either
<i><a href="sigemptyset.html">sigemptyset()</a></i>
or
<i><a href="sigfillset.html">sigfillset()</a></i>
at least once for each object of type
<b>sigset_t</b>
prior to any other use of that object.
If such an object is not initialised in this way, but is
nonetheless supplied as an argument to any of
<i><a href="sigaction.html">sigaction()</a></i>,
<i><a href="sigaddset.html">sigaddset()</a></i>,
<i><a href="sigdelset.html">sigdelset()</a></i>,
<i>sigismember()</i>,
<i><a href="sigpending.html">sigpending()</a></i>
or
<i><a href="sigprocmask.html">sigprocmask()</a></i>,
the results are undefined.
</blockquote><h4><a name = "tag_000_008_648">&nbsp;</a>RETURN VALUE</h4><blockquote>
Upon successful completion,
<i>sigismember()</i>
returns 1 if the specified signal is a member of the specified set, or 0 if it
is not.  Otherwise, it returns -1 and sets
<i>errno</i>
to indicate the error.
</blockquote><h4><a name = "tag_000_008_649">&nbsp;</a>ERRORS</h4><blockquote>
The
<i>sigismember()</i>
function may fail if:
<dl compact>

<dt>[EINVAL]<dd>
The
<i>signo</i>
argument is not a valid signal number,
or is an unsupported signal number.

</dl>
</blockquote><h4><a name = "tag_000_008_650">&nbsp;</a>EXAMPLES</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_008_651">&nbsp;</a>APPLICATION USAGE</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_008_652">&nbsp;</a>FUTURE DIRECTIONS</h4><blockquote>
None.
</blockquote><h4><a name = "tag_000_008_653">&nbsp;</a>SEE ALSO</h4><blockquote>
<i><a href="sigaction.html">sigaction()</a></i>,
<i><a href="sigaddset.html">sigaddset()</a></i>,
<i><a href="sigdelset.html">sigdelset()</a></i>,
<i><a href="sigfillset.html">sigfillset()</a></i>,
<i><a href="sigemptyset.html">sigemptyset()</a></i>,
<i><a href="sigpending.html">sigpending()</a></i>,
<i><a href="sigprocmask.html">sigprocmask()</a></i>,
<i><a href="sigsuspend.html">sigsuspend()</a></i>,
<i><a href="signal.h.html">&lt;signal.h&gt;</a></i>.
</blockquote><h4>DERIVATION</h4><blockquote>
Derived from the POSIX.1-1988 standard.
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UNIX &reg; is a registered Trademark of The Open Group.<br>
Copyright &copy; 1997 The Open Group
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